Electronic musical instrument capable of generating musical tone signals simulating the sounds of a wind instrument

ABSTRACT

An electronic musical instrument produces musical tones simulating a natural flute voice closely. The instrument comprises a fundamental tone-pitched signal generator, a keyer associated with a key and keying the signal from the generator with an amplitude responsive to a depressing force of the key, a filter giving a tone color, as a formant component, of the flute voice to the keyed signal from the keyer, a tone pitched noise generator with a percussive envelope having a peak amplitude which is less responsive to the key-depressing force than the amplitude of the fundamental tone pitched signal, or not responsive to the key-depressing force. The tone signal having the flute formant and the noise signal having the pitch sense are mixed and radiated from a loudspeaker.

United States Patent [72] Inventor TakeshiAdachi 3,247,309 4/1966 Campbell 84/1.26 X Hamamatsu, Japan 3,248,470 4/1966 Markowitz et al.. 84/1.1 [21] Appl. No. 21,079 3,250,843 5/1966 Jenny 84/l.09 [22] Filed Mar. 19, 1970 3,255,293 6/1966 Walker...,,... 84/l.1 [45] Patented Nov. 2,1971 3,439,106 4/1969 Goodale 84/l.27 [73] Assignee Nippon GakkiSeizo KabushikiKaisha 3,524,375 8/1970 Hopping 84/ 1.13 Hamamatsu-shi, Shizuoka-ken, Japan OTHER REFERENCES Pnomy 232: 1969 Culver; Charles A., Musical Acoustics, Fourth Edition, 44/214 1956,McGraw-I-l|ll Book Company, Inc.,pp. 198- 201.

Primary Examiner-D. X. Sliney Assistant ExaminerStanIey J. Witkowski [54] ELECTRONIC MUSICAL INSTRUMENT CAPABLE Attorney-Kcmon, Palmer & Estabrook OF GENERATING MUSICAL TONE SIGNALS SIMULATING THE SOUNDS OF A WIND INSTRUMENT ABSTRACT: An electronic musical instrument produces 16 Claims, 13 Drawing Figs. musical tones simulating a natural flute voice closely. The instrument comprises a fundamental tone-pitched signal genera- 521 U.S.C1. S t/1.22, tor a key" associated with a key and keying the signal from 84/1.1,84/1.17,84/1.19,84/1.26 51 I t Cl Gloh 1/02 the generator with an amplitude responsive to a depressing 'i 1 force ofthe key, a filter giving a tone color, as a formant com. I l 0 re 23 27 ponent, of the flute voice to the keyed signal from the keyer, a

tone pitched noise generator with a percussive envelope having a peak amplitude which is less responsive to the key- [56] References Cited depressing force than the amplitude of the fundamental tone pitched signal, or not responsive to the key-depressing force. UNITED STATES PATENTS The tone signal having the flute formant and the noise signal PBICISOD having the pitch sense are mixed and radiated from a loud- 3,328,506 6/1967 Park 84/l.26 X Speaker I 1 13 I4 I I I FUNDAMENTAL TONE PITCHED KEYER FILTER 2| 22 SIGNAL GENERATOR I I2 I? AMPLIFIER VARIABLE TOUCH RESPONSIVE RESISTOR- KEYBOARD SECTION ELEMENT 15 LED i TONE PITC NOISE SIGNAL GENERATOR l l I :18

WAVE SHAPING CIRCUIT PAIENTfnuuvz IS'II SHEET7UF 7 40 KSII SIGNAL O SOURCE FILTER 7|2 V*,. L 702 722 i HIGH Q s I52 FILTER2 i I m TOn 5 J HIGH Q FILTERn WAVE SHAPING CIRCUIT INVENTOR.

BY flaw; M

/ mdi (1 mm ELECTRONIC MUSICAL INSTRUMENT CAPABLE OF GENERATING MUSICAL TONE SIGNALS SIMULATING THE SOUNDS OF A WIND INSTRUMENT BACKGROUND OF THE INVENTION The present invention relates to an electronic keyboard musical instrument and more particularly to a novel type of said musical instrument which is so improved as to generate musical tone signals closely resembling the sounds of a desired wind instrument.

With a wind musical instrument, for example, a flute, there is generally generated at the start not only a sound component bearing the tone color of formant forming components which is sustained for a relatively long period, but also another sound component bearing the tone color of noise components which is sustained for a relatively short period. Such wind instrument is further characterized in that when it is blown soft, the formant component becomes soft and the noise-type sound component appears rather prominent, though only at the initial stage, whereas when it is blown forcefully, the formant component sounds loud and the noise component is not much noticed.

' However, the prior art electronic musical instrument of the kind is primarily designed to form musical tone signals bearing a tone color which only approximates that of a formant component included in the sounds generally produced by a natural wind instrument. Accordingly, although, while being continuously played, the conventional electronic musical instrument appears to produce sounds which relatively resemble those of a natural wind instrument, it generates in fact musical tones which widely depart from natural ones.

SUMMARY OF THE INVENTION The present invention has been accomplished to resolve the drawbacks encountered with the conventional electronic musical instrument and provide a novel type of said musical instrument wherein there is formed at the start not only a fundamental tone-pitched signal component bearing a tone color closely resembling that of formant component included in the sounds of a desired natural wind instrument and sustaining itself for a relatively long period, but also a tone-pitched noise signal component having a tone color closely resembling that of noise component included in the sounds of said natural wind instrument, whereby there can be played musical tones more resembling the sounds of a natural wind instrument than has been possible with the prior art.

BRIEF EXPLANATION OF THE DRAWINGS FIG. 1 is a schematic block diagram of an electronic musical instrument according to an embodiment of the present inventron;

FIGS. 2A and 2B show the concrete circuit arrangements of the various sections of the circuitry of FIG. 1;

FIGS. 3A to 3C illustrate the manner in which there is defined the tone pitch of output signals from the fundamental tone-pitched signal generator shown in FIG. 1 relative to that of output signals from the tone-pitched noise signal generator shown therein;

FIGS. 4A to 4C represent the different envelope forms of musical tone signals generated by the electronic musical instrument of the invention;

FIGS. 5 and 6 indicate different modifications of the cir cuitry of FIG. 1;

FIG. 7 is a modified schematic block diagram of the tonepitched noise signal generator of FIG. 2B, and

FIG. 8 represents a modified circuit of the section of a variable resistance element included in FIG. 2A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT There will now be described by reference to the appended drawings an electronic musical instrument according to the generates a DC voltage whose level varies, as later described,

with the magnitude of a force with which there is depressed a key during performance. Output signals from the section 12 are supplied to a keyer 13 having the later described circuitry as keying signals corresponding to fundamental tone-pitchedsignals from the generator 11. With this arrangemennthere are generated from the keyer 13 output signals which are obtained by controlling the voltage level of fundamental tonepitched signals from the generator 11 by that of keying signals from the section 12. Output signals from the keyer 13 are impressed on a filter 14 to form a fundamental tone-pitched signal component bearing a tone color well resembling that of a formant component included in the sounds of a desired wind instrument, for example, a flute.

Further there is provided a tone-pitched noise signal generator 15 which generates a tone-pitched noise signal component having a tone color well resembling that of the noise component of the sounds of said flute in correspondence to the depressed key as in the case of fundamental tone pitched signal generator 11. Tone-pitched noise signals from the noise signal generator 15 are conducted through a first normally open keying switch 16 which is only closed at the depression of its corresponding key to a variable resistance element 17 consisting of the later described field effect transistor (hereinafter referred to as FET) or a photoelectiric converting means. This element 17 serves as a percussion keyer. The control terminal of the variable resistance element 17 is supplied with a signal which is obtained by conducting, for example, a DC voltage from an indicated DC source 20 through the later described wave shaping circuit 19 via a second normally open keying switch 18 which is closed in interlocking relationship with the first keying switch 16. With such arrangement, there is obtained from the variable resistance element 17 the aforesaid tone-pitched noise signal component from the noise signal generator 15 only while said element 17 is in an operative state, namely, while its control electrode is supplied with a signal from the wave-shaping circuit 19. Output signals from the filter 14 and from the resistance element 17 are composed and these composite signals are supplied to a loudspeaker 22 through an amplifier 21, thereby reproducing through the loudspeaker 22 musical tones closely resembling the sounds of a natural flute. FIGS. 2A and 28 represent the concrete circuit arrangements of the various sections of the circuitry of FIG. I. The fundamental tone-pitched signal generator 11 preferably consists of a bistable multivibrator 111 comprising, for example, two NPN-type transistors TR, and TR, shown in FIG 2A, and being triggered synchronously by an upper stage. From the output terminal 31 of the multivibrator 111 are obtained fundamental tone-pitched pitched signals e, having a tone pitch corresponding to the depressed key whose frequency is designated as f, and also assuming a waveform of a rectangular one having a frequency spectrum as shown in FIG. 3A. The touch-responsive keyboard section 12 has a permanent magnetic piece 33 fitted to the underside of the depressed end of each of a plurality of keys 32 juxtaposed on keyboard. There is provided a coil 34 at a position where there is cut a magnetic flux from the magnetic piece 33 depressed together with a given key. The coil 34 is connected between the base and emitter terminals of an NPN-type emitter-grounded transistor TR, to supply input signals thereto. The collector terminal of the transistor TR, whose collector resistor R, is connected to the terminal 35p of a +B source is connected through a diode D, of the indicated polarity to the base terminal of an NPN- type emitter-follower transistor TR, The base terminal of the is further connected to the contact of a diode D of theindicated polarity and a capacitor C included in a series circuit consisting of a resistor R the diode D and capacitor C which are connected in series between the +8 source terminal 35;: and a grounded B source terminal 35n. There is interposed between the contact of the resistor R and diode D and the B source terminal 35n a third keying switch 36 operated in interlocking relationship with the first and second keying switches 16 and 18. There is connected in parallel a series circuit consisting of a resistor R, and capacitor C between both terminals of an emitter resistor R interposed between the emitter terminal of the transistor TR and B source terminal 35n. The contact 37 of the resistor R, and capacitor C, constitutes the output terminal of the touchresponsive keyboard section 121 and the transistor TR is supplied in advance with a base bias voltage by suitably setting the value of the resistor R so as to allow saturated current to be introduced while the corresponding key is not depressed.

Since the touch-responsive keyboard section 121 of the aforementioned arrangement allows saturated current to fiow through the transistor TR. while the corresponding key is not depressed, the potential of the output terminal 37 is maintained at substantially the same level as that of the +3 source. When the corresponding key is depressed, there is induced in the coil 34 an AC voltage whose level varies with the magnitude of a force with which the key is depressed. After being amplified during passage through the transistor, the AC voltage is further rectified while travelling through the diode D into a DC voltage of the negative polarity whose level varies with the magnitude of a force with which the key is depressed. The DC voltage obtained from the diode D is supplied to the transistor TR, as an inverse-base-bias voltage, and said third keying switch 36 is closed in interlocking relationship with the depression of the key, so that the transistor TR, acts as a sort of C-class amplifying circuit which is only controlled by a base-bias voltage supplied through the diode D Accordingly, when the key is depressed, there is obtained from the output terminal 37 of the touchresponsive keyboard section 121 the so-called touch-responsive negative DC voltage e in the pulse form whose level varies with the magnitude of a force depressing the key and whose time width extends from the depression to the release of the key. It will be apparent that the rising and decaying properties of said pulsative DC voltage e from said output terminal 37 are determined by the time constant of a charging and discharging circuit substantially consisting of the two resistors R and R and the capacitor C The input terminal 38 of the keyer 131 is supplied with output signals e, from the multivibrator 111 through a coupling capacitor C and also with output signals e from the touchresponsive keyboard section 121 through a resistor R To the input terminal 38 are connected the cathode terminals of two serially connected diodes D and D and between the contact of the two diodes D and D, and the grounding point is connected a bypass capacitor C Between the anode terminal of the diode D, and the grounding point is connected another bypass capacitor C same anode terminal is connected to the later described filter 141 through a resistor R and coupling capacitor C Between the contact of said resistor R and coupling capacitor C, and the grounding point is connected a resistor R The keyer 131 thus arranged allows its input terminal 38 to which there is connected the cathode terminal of the diode D to be supplied with a substantially +B source voltage through the output terminal 37 of the touch-responsive keyboard section 121 while the corresponding key is not depressed, so that the keyer 131 is kept at an OFF state when the corresponding key is not depressed, and when the key is depressed the input terminal 38 of the keyer 131 is supplied through the output terminal 37 of the touch-responsive keyboard section 121 a more negative DC voltage e substantially in the pulse from whose peak level is determined in accordance with the magnitude of a force with which the key is depressed, bringing the keyer 131 to an ON state. Thus output signals from the touchresponsive keyboard section 121 are supplied to the keyer 131 as a sort of keying (triggering) signal. From an output terminal 39 of the keyer 131 are obtained output signals corresponding to tone signals from the tone signal generator 111 only while the corresponding key is depressed. The level of the output signals is determined in accordance with the magnitude of a force depressing the key.

Since, in this case, the capacitor C and resistor R form a sort of differentiating circuit, signals e appearing at the input terminal of the keyer 131 assume a differentiated waveform. And the two diodes D and D and two capacitors C and C jointly constitute an integrating circuit, so that signals e appearing at the output terminal 39 of the keyer 131 bear an integrated waveform. The signals e having an integrated waveform which are obtained from the output terminal 39 of the keyer 131 are supplied to the filter 141 consisting of two vertically inverted L-shaped circuits respectively comprising a group of a resistor R and capacitor C and a group of a resistor R and capacitor C in order to form a tone-pitched signal component e bearing a tone color resembling that of a formant component included in the sounds of a desired wind instrument, for example, a flute.

The tone-pitched noise signal generator 151 includes a white noise source 40 including, for example, an NPN-type transistor TR; Shown in FIG. 2B. The emitter terminal of the transistor TR is connected to the +13 source terminal 35 White noise signals generated from the white noise source 40 formed by grounding the base terminal of the transistor TR through a resistor R are introduced through a high-cut filter 41 provided, if necessary, and arranged similarly to the aforementioned filter 141 so as to have their high-frequency component cut, and thereafter through an amplifier 42 comprising, for example, three indicated cascade connected NPN- type transistors TR ,TR and TR to be amplified. A balanced modulator 43 included in the electronic musical instrument of the present invention is arranged in the following manner. Terminals constituting one of the two pairs of balanced terminals included in a full-wave-recitfying diode switch consisting of four diodes D D D and D are respectively used as input and output terminals of signals. To the input and output terminals are connected an input transformer Tin and output transformer Tout each consisting of a primary and secondary coil. Between the neutral points of the input and output transformers is interposed a modulation transformer Tmod similarly comprising a primary and secondary coil. The aforesaid noise signals amplified by the amplifier 42 are supplied to the input transformer Tin of the balanced modulator 43. The modulation transformer Tmod of the balanced modulator 43 is supplied with output signals from a second tone signal generator 44 having substantially the same circuit arrangement as the first tone signal generator 111 further provided with associated key switches and keyers and, when there is depressed a given key, generating tone signals of a sine or rectangular waveform having a tone pitch twice or equal to that of signals 2 1 from said first tone signal generator 111 after said output signals are amplified by an amplifier 45 formed by connecting, as illustrated, two NPN-type transistors TR and TR in cascade relationship. With such arrangement, from the output transformer Tout of the balanced modulator 43 are obtained modulated signals which are formed by balanced modulating noise signals supplied from the input transformer Tin using signals supplied from the modulation transformer Tmod. The signal taken out from the output transformer Tout is essentially a noise signal but has a somewhat pitch sensation, the signal being e or e having a frequency spectrum as shown in FIG. 3B or 3C, as the signal contains a narrow band of frequencies close to the intended pitch frequency and approving in a random manner thereabout.

The variable-resistance element 17 includes FET 171 formed by grounding, for example, its source terminal S and drain terminal D through resistors R and R respectively as shown in FIG. 2A. When there is depressed a given key, the modulated signal corresponding thereto is supplied to the source terminal S or drain terminal D of FET 171 through the first keying switch 16 and a coupling capacitor C The shaping circuitry 191 should preferably be composed, for example, by connecting in cascade relationship a differentiating circuit 46 consisting of a capacitor C and resistor R an integrating circuit 47 consisting of a PNP-type emitter follower transistor TR and acapacitor C and an amplifier including an NPN-type common-emitter transistor u- When there is depressed a given key, the corresponding second keying switch 18 is closed, so that there are obtained from an output terminal 49 of the aforementioned circuitry 191 the signals which are generated by differentiating a pulsative DC voltage from the DC source 211 by the differentiating circuit 46 and further integrating the differentiated signals by the integrating circuit 47. The resultant signals are supplied to the control terminal of FET 171, or a gate terminal G.

The reason why the tone pitch of tone-pitched signals from the second tone-pitched signal generator 44 is chosen to be twice or equal to that of tone-pitched signals from the first tone-pitched signal generator 111 is that the noise component included in the sounds of a natural flute essentially consists of that range of tone pitches and that any pitch higher or lower than that range will appreciably depart from the noise component of the natural flute sounds, undesirably resulting in unnatural flute sounds which will render the difference more prominent. For the same reason, white noise signals from the white noise source 44 are first allowed to pass through the high-cut filter 41 to have their high-frequency component cut and then supplied to the input transformer Tin of thebalanced modulator 43.

With the electronic musical instrument of the present invention arranged as described above, when there is depressed a given key, there is obtained from the filter 141 fundamental tone-pitched signals e having a tone color well resembling that of a formant component included in the sounds of a natural flute. Moreover, the tone'pitched signals e, are controlled in keying by the aforementioned keying signals from the touch-responsive keyboard section 121 and sustained for a relatively long length of time while said key is depressed, their voltage level being determined in accordance with the magnitude of a force with which the key is depressed. In FIG. 4A, the upper line E indicates an envelope level of the signal when the key is struck strongly, while the lower line E indicates an envelope level of the signal when the key is struck softly. At this time there is obtained from the drain terminal D (or source terminal S) of FET 171 a tone-pitched noise signal component B, illustrated in FIG. 4A which well resembles the noise component included in the sounds ofa natural flute. The tone-pitched noise component B, is sustained for a relatively short length of time corresponding to the period during which signals obtained by introducing a DC voltage from the DC source 20 through the shaping circuitry 191 consisting of the differentiating and integrating circuits 46 and 47 are supplied to the gate terminal G of FET 171 (The duration is determined by the time constants of the differentiating and integrating circuits 46 and 47, and, in this embodiment, is chosen to be 50 milliseconds.) Moreover, the voltage level of the noise component B, does not vary, though the force of depressing the key may change in magnitude.

Accordingly, the electronic musical instrument of the present invention wherein a fundamental tone-pitched signal component from the filter 141 and a tone-pitched noise signal component from F ET 171 acting as a variable-resistance element are composed and musical tones consisting of the composite signals are regenerated through the loudspeaker 22, is capable of producing musical tones more closely resembling the sounds of a natural flute than has been possible with the prior art electronic musical instrument which is designed to simulate the sounds only by generating tone-pitched signals having a tone color approximating a formant component included in the natural flute sounds.

FIGS. 5 and 6 present different modifications of the circuitry of FIG. 1. In FIG. 1, output signals from the touchresponsive keyboard section 12 are supplied to the keyer 13 only as keying signals for fundamental tone pitched signals from the fundamental tone-pitched signal generator 11. In contrast, FIG. 5 represents the case where the touch responsive DC voltage is also, but in a smaller rate, supplied to the wave-shaping circuit 19 in place of the DC source 20.

In FIG. 6, the touch responsive DC voltage is further supplied to the variable resistor element 17 in addition to the keying signal from the wave shaping circuit 19.

According to the arrangement of FIG. 5, the voltage level of a tone pitched noise signal component E, as well as that of a fundamental tone pitched signal component 5, obtained from the filter 14 is determined in accordance with the magnitude of a force with which there is depressed a key as shown in FIG. 4B, in which the upper line E indicates an envelope level of the noise signal when the key is struck strongly and the lower line E indicates an envelope level of the noise signal when the key is struck softly. The modification of FIG. 6 displays, as shown in FIG. 4C, substantially the same effect as that of FIG. 5, but in addition the tone-pitched noise signal component is kept continuously generated at lower level while there is depressed the corresponding key, like the fundamental tonepitched signal component, though the voltage level of the former is appreciably more reduced as shown than at the start. In this case, it will be apparent that the voltage level E, of the tone-pitched noise signal component varying with the magnitude of a force depressing a key varies to a slightly smaller extent than the variation of the voltage level E,.

FIG. 7 is a modified schematic block diagram 152 of the tone-pitched noise signal generator 151 of FIG. 28. White noise signals from the white noise source 40 are supplied to high Q filters 711, 712 71:: provided for each key through keying switches 701, 702 70n and switched in interlocking relationship with the corresponding keying switches 16, 18 and 36. The same construction is well known in the art as described in the US. Pat. No. 2,694,954. When there is depressed the corresponding key, each of said high Q filters 711 to 71n is so designed as to obtain from the respective output terminals 721, 722 72n tone-pitched noise signal com ponents having a tone pitch twice or equal to that of the formant component E The present inventors experiments prove that as compared with the case where there is used such a balanced modulator as shown in FIG. 2B, the arrangement of FIG. 7 slightly decreases in the ability of cutting a highfrequency component included in said while noise signal and that use of the balanced modulator of FIG. 28 generates musical tones having a tone color more closely resembling that of natural flute sounds.

FIG. 8 represents a modified circuit of the section ofa variable resistance element included in FIG. 2A. According to FIG. 8, FET 171 is substituted by a photoelectric converting element, for example, a phototransistor 172. A light-responsive resistor such as a CdS cell will also do. There is provided light means at a point facing the light receiving plane of the phototransistor 172, the light means 80 being illuminated or extinguished depending on the type of output signals from the shaping circuit 19. The arrangement of FIG. 8 is capable of substantially the same operation and effect as in the foregoing embodiments.

Iclaim:

1. An electronic musical instrument comprising a keyboard having a plurality of juxtaposed keys operatively connected to touch-responsive keyboard sections for generating a DC voltage whose level varies with the magnitude of a force with which the keys of said keyboard are depressed, a first circuit means for forming a fundamental tone-pitched signal component having a tone color resembling that of a formant component included in the sounds of a wind instrument sustainable for a length of time fully controlled by the output from said touch-responsive keyboard section, a second circuit means for forming a tone-pitched noise signal component having a tone color resembling that of a noise component included in the sounds of said wind instrument sustainable for a relatively short length of time not fully controllable by said keyboard and signal mixing means which compose signal components from both said first and second circuit means into musical tones consisting of composite signals for reproduction through a loudspeaker.

2. The musical instrument according to claim 1 wherein each of said touch-responsive keyboard sections comprises a permanent magnetic piece integrally fitted to the underside of the depressed end of each key, a coil facing the position at which said permanent magnetic piece is depressed when the corresponding key is depressed, so as to cut a magnetic flux from said magnetic piece and rectifying means for rectifying an AC current induced across both ends of said coil.

3. The musical instrument of claim 1 wherein said first circuit means fonns a signal component having an envelope of sustained substantially constant level and the pitch of the tone of said noise signal is at least equal to that of said formant component signal. 4. The musical instrument of claim 1 which simulates a natural flute voice and comprises a fundamental tone-pitched signal generator, a key, a keyer associated with said key and keying the signal from said generator with an amplitude responsive to a depressing force applied to said key, a filter giving a tone color as a formant component of the flute voice to the keyed signal from said keyer, a tone-pitched noise generator and a percussion keyer associated with said key for keying the signal from said tone-pitched noise generator with an amplitude not responsive to said depressing force.

5. The musical instrument according to claim 1 wherein said first circuit means comprises fundamental tone-pitched signal generators for generating fundamental tone-pitched signals having a tone pitch corresponding to a given depressed key, keyers for controlling output signals from said generator corresponding to said depressed key in keying action using output signals from said touch-responsive keyboard section as keying signals and filters supplied with output signals from the keyer corresponding to said depressed key.

6. The musical instrument according to claim 1 wherein said second circuit means comprises a white noise signal source for generating white noise signals, a filter for drawing out only a desired frequency component included in said white noise signals, tone signal generators for generating tone signals having a tone pitch corresponding to a given depressed key, balanced modulators for modulating white noise signals obtained from said filter by tone signals from said generator corresponding to said depressed key, variable-resistance elements supplied with output signals from said modulators and provided with a control electrode and control signal sources for supplying control signals to obtain from said resistance elements output signals from said modulators.

7. The musical instrument according to claim 1 wherein said second circuit means comprises a white noise signal source for generating white noise signals, high Q filters which are supplied with said white noise signals through keying switches interlockingly switched with a given depressed key so as to form tone-pitched noise signals having a tone pitch corresponding to said depressed key, variable resistance elements supplied with output signals from said filters and provided with a control electrode and control signal sources for supplying control signals to obtain from said elements output signals from said filters while the control electrode of said elements is supplied with signals.

8. The musical instrument according to claim 6 wherein the end of said variable-resistance elements through which there are supplied output signals from said balanced modulators is also supplied with output signals from said touch-responsive keyboard sections so as to cause the voltage level of output signals from said balanced modulators is vary with the magnitude of a force with which there is depressed a key.

9. The musical instrument according to claim 6 wherein said variable-resistance elements consist of field effect transistors.

10. The musical instrument according to claim 7 wherein said variable-resistance elements consist of field effect transistors.

11. The musical instrument according to claim 6 wherein said variable-resistance elements consist of photoelectric converting elements.

12. The musical instrument according to claim 7 where in said variable-resistance elements consist of photoelectric converting elements.

13. The musical instrument according to claim 6 wherein said control signal sources comprise DC sources and shaping circuits, including differentiating and integrating circuits which are supplied with a DC voltage from said DC sources through keying switches interlockingly switched with a given depressed key.

14. The musical instrument according to claim 7 wherein said control signal sources comprise DC sources and shaping circuits, including differentiating and integrating circuits which are supplied with a DC voltage from said DC sources through keying switches interlockingly switched with a given depressed key.

15. The musical instrument according to claim 6 wherein said control signal sources utilize output signals from said touch-responsive keyboard sections.

16. The musical instrument according to claim 7 wherein said control signal sources utilize output signals from said touch-responsive keyboard sections.

i I! I t 

1. An electronic musical instrument comprising a keyboard having a plurality of juxtaposed keys operatively connected to touchresponsive keyboard sections for generating a DC voltage whose level varies with the magnitude of a force with which the keys of said keyboard are depressed, a first circuit means for forming a fundamental tone-pitched signal component having a tone color resembling that of a formant component included in the sounds of a wind instrument sustainable for a length of time fully controlled by the output from said touch-responsive keyboard section, a second circuit means for forming a tone-pitched noise signal component having a tone color resembling that of a noise component included in the sounds of said wind instrument sustainable for a relatively short length of time not fully controllable by said keyboard and signal mixing means which compose signal components from both said first and second circuit means into musical tones consisting of composite signals for reproduction through a loudspeaker.
 2. The musical instrument according to claim 1 wherein each of said touch-responsive keyboard sections comprises a permanent magnetic piece integrally fitted to the underside of the depressed end of each key, a coil facing the position at which said permanent magnetic piece is depressed when the corresponding key is depressed, so as to cut a magnetic flux from said magnetic piece and rectifying means for rectifying an AC current induced across both ends of said coil.
 3. The musical instrument of claim 1 wherein said first circuit means forms a signal component having an envelope of sustained substantially constant level and the pitch of the tone of said noise signal is at least equal to that of said formant component signal.
 4. The musical instrument of claim 1 which simulates a natural flute voice and comprises a fundamental tone-pitched signal generator, a key, a keyer associated with said key and keying the signal from said generator with an amplitude responsive to a depressing force applied to said key, a filter giving a tone color as a formant component of the flute voice to the keyed signal from said keyer, a tone-pitched noise generator and a percussion keyer associated with said key for keying the signal from said tone-pitched noise generator with an amplitude not responsive to said depressing force.
 5. The musical instrument according to claim 1 wherein said first circuit means comprises fundamental tone-pitched signal generators for generating fundamental tone-pitched signals having a tone pitch corresponding to a given depressed key, keyers for controlling output signals from said generator corresponding to said depressed key in keying action using output signals from said touch-responsive keyboard section as keying signals and filters supplied with output signals from the keyer corresponding to said depressed key.
 6. The musical instrument according to claim 1 wherein said second circuit means comprises a white noise signal source for generating white noise signals, a filter for drawing out only a desired frequency component included in said white noise signals, tone signal generators for generating tone signals having a tone pitch corresponding to a given depressed key, balanced modulators for modulating white noise signals obtained from said filter by tone signals from said generator corresponding to said depressed key, variable-resistance elements supplied with output signals from said modulators and provided with a control electrode and control signal sources for supplying control signals to obtain from said resistance elements output signals from said modulators.
 7. The musical instrument according to claim 1 wherein said second circuit means comprises a white noise signal source for generating white noise signals, high Q filters which are supplied with said white noise signals through keying switches interlockingly switched with a given depressed key so as to form tone-pitched noise signals having a tone pitch corresponding to said depressed key, variable resistance elements supplied with output signals from said filters and provided with a control electrode and control signal sources for supplying control signals to obtain from said elements output signals from said filters while the control electrode of said elements is supplied with signals.
 8. The musical instrument according to claim 6 wherein the end of said variable-resistance elements through which there are supplied output signals from said balanced modulators is also supplied with output signals from said touch-responsive keyboard sections so as to cause the voltage level of Output signals from said balanced modulators is vary with the magnitude of a force with which there is depressed a key.
 9. The musical instrument according to claim 6 wherein said variable-resistance elements consist of field effect transistors.
 10. The musical instrument according to claim 7 wherein said variable-resistance elements consist of field effect transistors.
 11. The musical instrument according to claim 6 wherein said variable-resistance elements consist of photoelectric converting elements.
 12. The musical instrument according to claim 7 where in said variable-resistance elements consist of photoelectric converting elements.
 13. The musical instrument according to claim 6 wherein said control signal sources comprise DC sources and shaping circuits, including differentiating and integrating circuits which are supplied with a DC voltage from said DC sources through keying switches interlockingly switched with a given depressed key.
 14. The musical instrument according to claim 7 wherein said control signal sources comprise DC sources and shaping circuits, including differentiating and integrating circuits which are supplied with a DC voltage from said DC sources through keying switches interlockingly switched with a given depressed key.
 15. The musical instrument according to claim 6 wherein said control signal sources utilize output signals from said touch-responsive keyboard sections.
 16. The musical instrument according to claim 7 wherein said control signal sources utilize output signals from said touch-responsive keyboard sections. 